Add thread lock to glue model tokenizer call and update demos version.
Add thread lock to glue model tokenizer call and update demos version.

Fixes race condition when using multiple interpreters in separate threads of LIT server with same model.

PiperOrigin-RevId: 417452193

PAIR-code/lit,PAIR-code/lit,PAIR-code/lit,PAIR-code/lit,PAIR-code/lit